Sn Foil Research Articles

CuO-loaded nano-porous SnO 2 films fabricated by anodic oxidation and RIE process and their gas sensing properties

The fabrication of nano-porous SnO 2 films with 1-D nano-channels by anodic oxidation has been a challenge due to a collapse of pore structure during annealing process and an existence of non-porous upper barrier layer. A new approach is developed to synthesize the nano-porous SnO 2 films by employing Sn thin film instead of Sn foil and a reactive ion etching (RIE) process. The integrity of nano-porous structure was maintained by anodizing the Sn thin film deposited on SiO 2/Si substrate, and 1-D nano-channels were opened up by removing the non-porous layer by RIE. As a potential application to gas sensor, CuO was impregnated to the nano-porous SnO 2 films and their gas sensing properties were investigated. The nano-porous CuO–SnO 2 film sensors exhibited the enhanced sensitivity and selectivity toward H 2S gas, and their H 2S sensing mechanism was discussed in terms of the formation/disruption of resistive p-CuO/n-SnO 2 junction based on the variation of XPS binding energy and electrical resistance during gas exposure.

The phase transformations and cycling performance of copper–tin alloy anode materials synthesized by sputtering

A sputtering technique was adopted to synthesize Sn–Cu thin film electrodes. Island Sn particles were obtained on the copper foil. Cu 6Sn 5 was spontaneously generated at the interface between Sn and Cu foil. To further improve the cycling stability, Cu source was introduced to increase the formation of Cu 6Sn 5 and to serve as a buffer during cycling. Moreover, the phase and elemental ratio of Sn and Cu varied in the synthesized electrode by alternately adjusting sputtering time for Sn and Cu. The cell synthesized by sputtering Sn for 5 min and Cu for 9 s alternately exhibited the best cycling stability. The 1st charge capacity of cell was 635 mA hg −1, and the 1st efficiency was even higher than 97%. The capacity remained higher than 500 mA hg −1 after 15 cycles. The phase transformation of cell was investigated through voltage profile, CV curve and in situ XRD analysis. The in situ XRD analysis confirmed that Cu 6Sn 5 could react with lithium directly without the presence of Li 2CuSn during cycling. The reaction mechanism of Cu 6Sn 5 with lithium during cycling was demonstrated to be an alloying process, and the structure of Cu 6Sn 5 was thus a low-temperature monoclinic phase.

X-ray attenuation around K-edge of Zr, Nb, Mo and Pd: A comparative study using proton-induced X-ray emission and 241Am gamma rays

Mass attenuation coefficients (µ/ρ) for Zr, Nb, Mo and Pd elements around their K-edges are measured at 14 energies in the range 15.744–28.564 keV using secondary excitation from thin Zr, Nb, Mo, Rh, Pd, Cd and Sn foils. The measurements were carried out at the Kα and Kβ energy values of the target elements by two techniques: (1) Proton-induced X-ray emission (PIXE) and (2) 241Am (300 mCi) source. In PIXE, 2 MeV proton-excited X-rays were detected by a Si(Li) detector. In the second case, X-rays excited by 59.54 keV photons from the targets were counted by an HPGe detector under a narrow beam good geometry set-up with sufficient shielding. The results are consistent with theoretical values derived from the XCOM package and indicate that the PIXE data have better statistical accuracy.

Development of a New Multi Layer Substrate Bonding Technology using Ag-Sn Liquid Phase Sintering Process (First Report) -Investigations of Diffusion Processes-

In order to construct the multi layers IVH (Interstitial Via Hole) structure with only one time hot pressing, we have developed the new diffusion bonding technology. In this paper, the sintering process of Ag-Sn mixed powders (Ag/Sn:65/35 mass%) between copper foils in IVH with hot vacuum pressing was investigated, and the effect of temperature on the respective diffusion reactions was discussed. Ag and Sn formed Ag3Sn up to 473 K with the solid diffusion reaction. At 483 K, Ag particles disappeared completely and the mixed compact consisted of Ag3Sn and excess Sn. Cu-Sn diffusion reaction between excess Sn and copper foil commenced at 493 K. Excess Sn was consumed completely below 573 K. The liquid phase of Sn contributed not only to Cu-Sn diffusion bonding but also to Ag3Sn sintering. As a result of hot pressing above 573 K, the mechanical properties were improved without large grain growth of Ag3Sn (about 4 μm).

Gas-sensing properties of SnO2 nanobelts synthesized by thermal evaporation of Sn foil

Abstract The SnO2 nanobelts were prepared through simply thermal evaporation process of metallic tin foil at 1100 °C under ambient atmospheric pressure without any catalysts. The as-prepared products were characterized using X-ray powder diffraction (XRD), scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy (TEM), and selected-area electron diffraction (SAED). XRD and SAED results reveal that the products are pure and single-crystalline. The widths of nanobelts range from 400 to 600 nm, and the thickness is about 50 nm. The as-products are high sensitivity and fast response time to ethanol gas.

K-shell spectra from Ag, Sn, Sm, Ta, and Au generated by intense femtosecond laser pulses

K-shell X-ray spectra were recorded by the Dual Crystal Spectrometer (DCS) from Ag, Sn, Sm, Ta, and Au planar foil targets irradiated by single intense femtosecond pulses from the Titan laser at Lawrence Livermore National Laboratory. DCS implements two quartz crystals in transmission (Laué) geometry covering the X-ray energy range 10–50 keV and 20–120 keV. The spectral images were recorded on photo-stimulable phosphor image plates and on film/phosphor cassettes. The Kα and Kβ spectral lines of Ag with energies 22 keV and 25 keV, Sn at 25 keV and 28 keV, Sm at 40 keV and 46 keV, Ta at 57 keV and 66 keV, and Au at 67 keV and 79 keV were clearly resolved. The observation of these spectral lines, resulting from 1s electron vacancies created by electrons with energies up to at least 80 keV, enables the implementation of K-shell spectroscopy diagnostic techniques for understanding the laser energy deposition, energetic electron generation, ionization distribution, and X-ray conversion efficiency in plasmas produced by an intense femtosecond laser pulse. Based on the measured energies of the Au K-shell transitions, we conclude that the observed Au K-shell transitions are from ionization stages lower than Au +44, and are most likely from neutral Au atoms, that the Titan plasmas and the hard X-ray emissions are dominated by electrons with energies exceeding 80 keV, and that thermal processes play a minor role.

Porous SnO2 Films Fabricated Using an Anodizing Process

The measurement of specific gases is based on the reversible conductivity change of sensing materials in semiconductor type gas sensors. For an application as gas sensors of high sensitivity, porous <TEX>$SnO_2$</TEX> films have been fabricated by anodizing of pure Sn foil in oxalic acid and characteristics of anodic tin oxide films have been investigated. Pore diameter and distribution were dependent on process conditions such as electrolyte concentration, applied voltage, anodizing temperature, and time. Characteristics of anodic films were explained with current density-time curves.

Biomolecule‐Assisted Synthesis and Electrochemical Hydrogen Storage of Porous Spongelike Ni3S2 Nanostructures Grown Directly on Nickel Foils

Nanothread-based porous spongelike Ni3S2 nanostructures were synthesized directly on Ni foil by using a simple biomolecule-assisted method. By varying the experimental parameters, other novel Ni3S2 nanostructures could also be fabricated on the nickel substrate. The electrochemical hydrogen-storage behavior of these novel porous Ni3S2 nanostructures was investigated as an example of the potential properties of such porous materials. The thread-based porous spongelike Ni3S2 could electrochemically charge and discharge with the high capacity of 380 mAh g(-1) (corresponding to 1.4 wt % hydrogen in single-walled nanotubes (SWNT)). A novel two-charging-plateaux phenomenon was observed in the synthesized porous spongelike Ni3S2 nanostructures, suggesting two independent steps in the charging process. We have demonstrated that the morphology of the synthesized Ni3S2 nanostructures had a noticeable influence on their electrochemical hydrogen-storage capacity. This is probably due to the size and density of the pores as well as the microcosmic morphology of different nickel sulfide nanostructures. These novel porous Ni3S2 nanostructures should find wide applications in hydrogen storage, high-energy batteries, luminescence, and catalytic fields. This facile, environmentally benign, and solution-phase biomolecule-assisted method can be potentially extended to the preparation of other metal sulfide nanostructures on metal substrates, such as Cu, Fe, Sn, and Pb foils.

The dynamic range of ultra-high-resolution cryogenic gamma-ray spectrometers

We are developing high-resolution cryogenic gamma-ray spectrometers for nuclear science and non-proliferation applications. The gamma-ray detectors are composed of a bulk superconducting Sn foil absorber attached to a multilayer Mo/Cu transition-edge sensor (TES). The energy resolution of a detector with a 1×1×0.25 mm 3 Sn absorber is 50–90 eV FWHM for γ-rays up to 100 keV, and it decreases for larger absorbers. Here, we present the detector performance for different absorber volumes, and discuss the trade-offs between energy resolution and dynamic range.

江戸時代後期に作られた錫糸の微細構造と腐食

The microstructures and corrosion behavior of tin thread made in the late Edo period have been investigated. Specimens are obtained from brocades made using the tin thread and from a sample book of tin brocade. Reflectance is measured with a spectrophotometer. Fine structures are observed using a transmission electron microscope. An X-ray diffractometer and X-ray photospectrometer are used to identify corrosive matter. Sn foil glued on Japanese paper shows a brownish black color spectrum. The thickness of the corroded Sn foil is 8∼10 μm. SnO2, SnO, and Sn3O2(OH)2 are detected in the corroded Sn foil. The top layer consists of the most stable SnO2, and there is a SnO layer beneath the SnO2 layer. A Sn3O2(OH)2 layer exists between the SnO layer and the unreacted Sn layer. From these results, corrosion has been promoted in the order of Sn3O2(OH)2, SnO and SnO2.

Sn and SnBi Foil as Anode Materials for Secondary Lithium Battery

ABSTRACTIn order to better understand the cycling mechanism of metal alloy anodes, and to mitigate the capacity fade observed in lithium battery use a study of simple systems was initiated. Tin foil and tin-bismuth mixtures were chosen because there is no need for conductive diluents or binders so that the intrinsic behavior could be observed. A pure tin foil was found to react rapidly with lithium, ≥ 3 mA/cm2, and with no capacity fade for over 10 cycles. This is better than tin powder or electrodeposited tin. After the first cycle, the foil reacts with Li following a stepwise formation of different alloys as dictated by the thermodynamics. Incorporation of bismuth into the foil increased the capacity fade after the first few cycles, with the eutectic composition Sn0.57Bi0.43 having better capacity retention than the Sn0.5Bi0.5 composition. XRD and SEM-EDS shows that bismuth is rejected from the tin rich phase during lithium insertion and is not reincorporated on lithium removal, just as expected from the phase diagram.

Detecting of melting by changes of rear surface reflectivity in shocked compressed metals using an interferometric diagnostic method

When a high power laser (1012 W/cm2) irradiates a target, it induces a shock wave, which reaches the (free) rear surface. The free surface is accelerated and the shock wave is back-reflected as a rarefaction wave. In the shock wave pressure regime involved here, melting of the target during the shock or during the rarefaction may occur. An optically recording velocity interferometric system (ORVIS) has been developed to measure the time evolution of the change in the reflectivity of the free surface. Shock waves of the order of hundreds of kilobars are produced in 50–125 μm thick Sn and Al foils, by a Nd:YAG laser system with a wavelength of 1.06 μm, pulse width of 7 ns (FWHM), and irradiance in the range (1.4–2.4)·1013 W/cm2. The changes in the reflectivity occur along two time scales: a slow one, more than 17 ns in Al and more than 30 ns in Sn, and a rapid one, less than 2.5 ns, in both materials. A possible explanation for the sharp decreases in the time scale is that melting occurs during the release of the free surface.

Generation of hard transition X-rays by relativistic electrons in multilayered metal targets

Spectra of resonance transition X-rays (RTR) generated in a periodical target composed of 9 Sn foils 11 μm in thickness spaced by 52 μm have been measured. They are shown to be significantly narrowed due to the influence of the K-shell photoabsorption edge. The ratio between intensities of RTR and bremsstrahlung is discussed. In the X-ray spectra measured using an equivalent continuous 100 μm Sn target the density effect is masked by the contribution of the transition radiation generated on the two surfaces.

Surface characterization study of the chemical alteration of an air-exposed polycrystalline tin foil during H-atom exposures

An air-exposed polycrystalline Sn foil surface has been examined before and after exposure to H atoms using X-ray photoelectron spectroscopy (XPS) and ion scattering spectroscopy (ISS). The foil initially contains large amounts of oxygen and carbon at the surface. C is present mostly as hydrocarbon contamination, and O is present as Sn hydroxide and surface water in addition to SnO, SnO 2 and transitional oxide (possibly Sn 3O 4), which has an O content between SnO and SnO 2. The C and O contents of the near-surface region are significantly reduced by exposure to the H-atom flux. The large hydroxyl group concentration is reduced through formation and desorption of water. A short 1-min exposure results in reduction of some of the SnO 2 or transitional oxide to SnO. Longer reduction periods result in the formation of a large amount of transitional oxide and some metallic Sn. ISS data indicate that the O and C contents of the outermost atomic layer initially increase upon exposure to H atoms due to a chemically induced driving force and then decrease. Migration of subsurface C and O becomes the rate-limiting step with regard to further removal of these species at room temperature.

Nuclear inelastic scattering of synchrotron radiation by119Sn

We have investigated inelastic scattering of synchrotron radiation by ${}^{119}\mathrm{Sn}$ nuclei using the radiative channel of nuclear deexcitation. The energy dependence of nuclear scattering of the 23.8795-keV x rays by a $\ensuremath{\beta}$-Sn foil was measured with sub-meV energy resolution. In the conditions of the experiment the scattering was incoherent over the various nuclei and averaged over the phonon momentum transfer. The experimental data are compared with the theory of nuclear inelastic absorption. The general agreement is reasonable, however, some deviation is noted. The possible origin of the discrepancy is discussed.

Radiation from relativistic electrons in homogeneous condensed matter at large angles (≫γ−1)

The radiation spectra from 900 and 400 MeV electrons in thin Ta, Cu, and Sn foils are measured at an angle of 19° with respect to the direction of motion of the beam. The radiation yield and its dependence on the electron energy agree satisfactorily with the theory of polarization bremsstrahlung. This result represents the first direct observation of polarization bremsstrahlung from ultrarelativistic electrons in homogeneous condensed matter.

Impact flash and debris cloud expansion of high-pure metal foils

Results of 2 mm aluminum spheres perforating Al, Cu, Mo, Au, Sn, and Zn metal foils of a purity > 99.9 % with thicknesses between 0.1 mm and 2.0 mm, densities of up to 20 g/cm 3, melting temperatures of 500 – 3000 K and specific heats of fusion of 20 – 350 kJ/kg at impact velocities between v p = 4.5 km/s and v p = 9 km/s are presented. The influence of target thickness, target material properties and impact velocity on the perforation hole diameter, impact flash duration and expansion velocity, fragmentation and debris cloud formation at nearly constant areal density is demonstrated. The dependence of impact crater pattern at witness plates on target material density, thickness, impact velocity and areal density ratio between projectile and target material is discussed. For tin and lead evidence is given for the ability of digital scanning electron microscope analysis as an effective tool for indicating change of aggregation from solid into liquid and for the determination of relative projectile and target material quantities.

Laser interferometric measurement of the surface tension of thin foils

A technique has been developed to measure the surface tension of thin foils under their own vapor pressure. The zero creep method of surface tension measurement is used in conjunction with laser interferometry. This technique allows very small sample strains to be measured. Sample length changes of the order of 0.3 μm were measured with the laser interferometer. The sensitivity of the laser interferometer/zero creep system allows the surface tension to be measured much closer to the Tammann temperature, which is approximately one-half the melting temperature (≍1/2 Tm) of the material. The system has been tested on thin Sn foils in air, and on thin Al and Ni foils under their own vapor pressure (vacuum).

Some X‐ray photoelectron spectroscopic measurements on Passivated Tin in some neutral media

AbstractSome ESCA measurements have been carried out on the anode film formed on BDH Sn foil by the potentiodynamic technique up to 2.5 V (SCE) in (i) phosphate buffer, pH 6.7, (ii) 0.1 M KCl, 0.1 M Na2SO4, pH 6.6, in order to identify the elements, and possibly also some compounds, present in the film. The results in phosphte buffer indicate the presence of: (i) Sn(II) and Sn(IV) oxides and hydroxides, (ii) tin phosphate species probably (HPO4)2−, (H2PO4)−, and insoluble phosphate complexes and (iii) evidence is given for the formation of soluble Sn species containing OH or phosphates before the beginning of passivity. The results in chloride solutions indicate the presence in the anode film of Sn, O and Cl in various states of combination such as: (i) Sn(II) and Sn(IV) species (oxides, chlorides and some hydroxides, (ii)) adsorbed oxygen and water, and (iii) basic or oxysalts or complexes involving Sn, O, Cl, and K. The results in Na2SO4 solutions indicate the presence in the film of Sn, O, S, and Na in the form of: (i) Sn(II) and Sn(IV) oxides and hydroxides, (ii) Na2SO4, other un‐ identified S species, and possibly also traces of PbS (from traces of Pb present in the Sn foil), (iii) adsorbed oxygen and water, and (iv) basic or oxysalts or complexes involving Sn, Na, O, sulphate and other unidentified S species.

Bio-corrosion: Solubilization and accumulation of metals by fungi

Penicillium colonies grown on thin foils of Er, Co, Cu, Zn, Cd, Al and Sn can solubilize the underlying metal leaving holes. Lead foil is stripped uniformly and Cu shows edge dissolution as well. The order of ‘corrodibility’ was Zn > Sn > Al > Pb > Cu > Er > Co. Among all the physical parameters examined, only melting point approximated this order. It was also demonstrated that the extraction of Fe from a stainless steel (Cr, Ni, Mo) was enhanced in the presence of the fungus. This dissolution did not require contact of metal with the fungus and was not accounted for by acidification.